Based on the erotic manga by Akatsuki Myuuto.

After being informed of his mother’s demise, Kengo returns to the hometown he had left seven years ago. There, he is reunited with a number of young girls, his half-sisters by his father’s mistresses. These girls have never been allowed out of the house, and have developed a fear of the outside. Kengo confronts his father in order to free the girls, but he is still terrified of the man.